1. Field of the Invention
This invention relates to the field of navigation devices or units, especially the Global Positioning System (hereinafter “GPS”) devices or units that have a visual display. In particular, it relates to a visor or sunshade that can be a permanent or removable part of a GPS device, or that can be a separate accessory that can be attached to a GPS unit, to improve the viewing of the information that appears on the visual display screen under bright light. Thus, it relates to a visor that has an attachment means to attach itself to GPS units that have a visual display, including portable GPS units that have a visual display. It also relates to a visor that comprises a supplemental antenna to provide improved reception of signals from GPS satellites. It also relates to a method of using such GPS device or visor to improve the viewing of information on the visual display screen and/or the reception of GPS satellite signals, an article of manufacture that provides such GPS device or visor; to the provision with the such GPS device or visor of instructions for use; and/or to methods of doing business that promote the availability and the utility of such GPS unit or visor, articles of manufacture, and methods, etc., to the plurality of people who may need such unit, visor, etc.
2. Description of the Related Art
GPS units or apparatus have become very popular with consumers for use as a navigation aid for movable bodies, such as motor vehicles, automobiles, trucks, motorcycles, boats, planes, and for activities such as hunting, hiking, fishing, camping, street walking, and the like. Some high-priced automobiles, boats, and planes have a GPS unit permanently installed in their control dashboard. However, the portable GPS units that can be temporarily installed are even more widespread. These portable and usually temporarily mountable GPS units can be removed and stored out-of-sight when not in use, or can be transferred to another vehicle, so one unit can be alternatively used in several vehicles. GPS units are commercially available in many models under the brand names of, e.g., Garmin™, Magellan™, Tom Tom™, Mio™, Cobra™, LG™, and the like.
In general, a portable GPS unit comprises a movable body comprising mainly an antenna, tuned to the frequencies transmitted by the satellites; a position measuring device for determining a self-position of the movable body; an input device for inputting a destination position; a memory device for storing map information and information about the course from the present position to the destination; an optimum course device for evaluating different courses from the present position to the destination by using the map information stored in the memory device and searching for the optimum course by selecting a course, based on some selection criteria, that is the best one among the various evaluated courses, as the optimum course; and a visual display device for providing the user with various information, such as, the present position, a road map that shows the directions toward the destination, the description of the different roads and streets for the present trip, and other information such as turn-by-turn directions, name of the roads, speed of the vehicle, projected time of arrival, and the like; a speaker means to announce some of the information such as the next turn; and a placement means or a mounting means to mount the GPS unit on a location of, e.g., a vehicle, such as on the dashboard or a windshield. Although the display screens for most portable GPS units are fairly small, with diagonal dimension of from about 3.5 cm to about 13 cm, they display a lot of information, from detailed maps with street names and directions for the next turn or the next several turns, and other information, such as speed of the vehicle, projected arrival time, nearby points of interest, such as gas stations, restaurants, hospitals, and the like. Another type of GPS unit comprises many of the functions listed above, but also comprises a mobile or cellular telephone device and/or other computer capabilities, to serve both as a GPS unit and a mobile phone unit and/or as a GPS unit and a personal digital assistant (PDA) unit, such as PDA units from Research in Motion™ Limited, Garmin, Mio, Navman™, Mobile Crossing™, Pharos™, Asus™, and the like.
For easy viewing by the user, portable GPS units are most often mounted on top of the dashboard or on the front windshield of a motor vehicle. In these positions, the display screen can become difficult to view at times, when the GPS device is exposed to bright light, e.g., bright sunlight. U.S. Pat. No. 7,413,233 B1 issued to Jung on Aug. 19, 2008 discloses a special display screen that is placed in tandem with the car sun visor to provide shading but which blocks more of the view of the road. Under bright sunlight that shines on the display screen, the image and information on the display screen of a dash-mounted or windshield-mounted GPS unit can appear dimmed and/or washed out, and the user may loose the visual directions, potentially causing hazardous driving conditions.
The extent of this problem has not been appreciated. Thus, there is a need for a visor or sunshade that has a means for attaching it to the GPS unit and which shields the glare of the bright sunlight from the display screen of said GPS unit, thus allowing a comfortable and clear reading by the driver of the information on said display screen. During night time driving, the lighted display screen of the GPS unit can reflect itself off the front windshield and cause diminished visibility of the road, especially on dark streets or unlit highways. There has been no recognition of this problem. Thus, there is a need for a shade on the GPS screen to block that reflection that appears on the windshield at night to provide the car driver with a good visibility of the road. The invention improves driving safety both during bright sunlight and at night.
The reception of satellite signals by a GPS unit can be improved by the use of an external or supplemental antenna, which can provide a stronger signal reception and/or a faster signal acquisition. A better signal reception can also reduce the risk of losing the signal lock. The performance of an antenna is dependent in part on its physical orientation, which is related to the radiation pattern of the antenna. There are many commercially available supplemental or external GPS antennas that can be purchased from the GPS unit manufacturers, such as Garmin and Magellan, and from GPS accessories manufacturers, such as Gilsson Technologies™, 2576 Barrington Court, Hayward, Calif. 94545. An external or supplemental GPS antenna generally comprises a housing containing an antenna unit that is linked by a coaxial cable to a coaxial connector. The coaxial connector in turn is attached to the external antenna jack of a GPS unit to transfer the signals received by the antenna to the GPS unit. A correct orientation of the antenna is needed for a good reception of satellite signals. A typical GPS antenna is a flat microstrip (or patch) antenna that provides a better reception when it is placed horizontally because satellite signals come from above. When used in a motor vehicle, the supplemental GPS antenna is usually placed horizontally on the roof of the vehicle, attached to the windshield, or placed horizontally on the dashboard, and is connected to the GPS unit by a long cable. There is a need to simplify the hook-up and attachment of the supplemental antenna to the GPS unit, and to maintain the approximately horizontal position for the antenna.
Despite the clear need for driving safety and convenience, there has been no recognition in the art of the problems solved by the invention.